Point-source X-ray imaging systems currently account for the greatest portion of medical X-ray imaging systems in the United States. Point-source X-ray imaging systems comprise an X-ray radiation source such as an X-ray tube that emits X-rays from a single discrete location or window. While point-systems have achieved a relatively high level of image resolution and imaging speed, they are limited by an unfavorable signal-to-noise ratio related to the position of the patient relative to the source and detector and provide data sufficient only for flat, e.g. two-dimensional, images.
X-ray imaging systems have been developed that address these latter two deficiencies. See for example U.S. Pat. No. 5,729,584 entitled “Scanning Beam X-Ray Imaging System,” issued to Moorman et al. In contrast to a point-source imaging system, this type of imaging systems utilizes an X-ray source having a plurality of discrete emissive locations on its face and a relatively small detector. The geometry of this type of imaging system both improves signal-to-noise ratios by decreasing the number of scattered X-ray photons collected and provides sufficient data to reconstruct a range of planes between the source and detector.
However, the spatial resolution and image fidelity provided by these systems can vary from plane to plane, and can range from being competitive with or better than advanced point-source systems and being quite poor. Embodiments of the present invention provide a method and apparatus of improving the resolution and image fidelity of such systems.